In recent years, mobile communication terminal apparatuses each having different wireless communication functions by different wireless band signals in the single terminal apparatus have become widespread.
For example, there exists a mobile communication terminal apparatus having both a mobile phone function of performing wireless communication as a so-called third-generation (to be referred to as “3G” hereinafter) mobile phone and a W-LAN communication function of performing wireless communication by connecting to an access point of wireless LAN (Wireless-Local Area Network: to be referred to as “W-LAN” hereinafter) communication. Such a mobile communication terminal apparatus is used not only as a mobile phone device but also as a W-LAN communication terminal apparatus such as an IP phone terminal or a high-speed Internet access terminal.
However, W-LAN communication by the mobile communication terminal apparatus can be executed only in a place where W-LAN communication is executable, for example, a home, an office, or a hot spot where a W-LAN connection service is provided. If the W-LAN communication function of the mobile communication terminal apparatus maintains an operative state even in a place where W-LAN connection is impossible, the W-LAN communication function wastes power.
To prevent the mobile communication terminal apparatus having the W-LAN communication function for wasting power, it is necessary to suppress wasteful power consumption by the W-LAN communication function under circumstances where the W-LAN communication function is unusable.
Techniques to solve this problem have been known, including a technique (patent literature 1) of detecting the position information of a mobile terminal using signals from GPS (Global Positioning System) satellites and comparing the detected position information with the position information of an access point registered in advance so as to control the power supply of a wireless LAN adapter, a technique (patent literature 2) of receiving notification information transmitted from a mobile phone base station to represent the presence/absence of a wireless LAN base station and controlling the power supply of a wireless LAN communication unit based on the received notification information, and a technique (patent literature 3) of storing the threshold of reception signal strengths from a plurality of adjacent base stations in cellular communication at a place where a wireless LAN access point can be detected and controlling the power supply of a wireless LAN communication unit based on the threshold.